Made available in DSpace on 2016-08-31T13:33:40Z (GMT). No. of bitstreams: 1 IsaacBTS_DISSERT.pdf: 5495741 bytes, checksum: 51971b46b62abac857269a023f55e88b (MD5) Previous issue date: 2014-12-19 / Microstrip patch antennas consist of a metallic strip over a dielectric substrate and widely used because of its small size and versatility of its dimensions and possible configurations of the patch to achieve specific characteristics of resonance frequency, bandwidth, directivity and return loss. Due this versatility of its parameters, this work presents a microstrip patch antenna proposal involving the insertion of two Complementary Split Ring Resonators (CSRR), as the variation of its dimensions, and will be developed a study of CSRR s influence in antenna s parameters, designed by Transmission Line Theory, with the objective of increasing the antenna s bandwidth and filtering certain frequencies; and manufacture a device which operates in Ultra Wideband (UWB) system. The application of dielectric multilayers will be also studied with the objective of evaluate its influence in antenna s return loss. The software ANSYS HFSS® was used as an auxiliary tool to simulate the antennas parameters and the best results, as well the evaluation about the available material, were used to build the devices and measure them to validate the results previously simulated. The simulations results matched with the expected behavior of the return loss, because the filter characteristic appeared in some frequencies and the result presented a dual-band characteristic. The experimental result for the return loss agreed with the simulated pattern, despite the dislocated frequency to higher values, but just one of the measured antennas could be used in the UWB system with fractional bandwidth of 34,12% in the resonance frequency of 4,35 GHz with return loss of -36,22 dB, allowing the operation in many wireless communication systems like the IEEE standards 802.11a, 802.11n and 802.11p / As antenas de microfita tipo patch (ou plaqueta) são antenas constituídas de um recorte metálico sobre um substrato dielétrico, e são bastante utilizadas devido ao seu tamanho reduzido e versatilidade em relação as diversas configurações e dimensões que podem ser utilizadas no patch a fim de alcançar características específicas de frequência de ressonância, largura de banda, diretividade e perda de retorno. Devido a essa versatilidade em relação aos parâmetros construtivos e eletromagnéticos, este trabalho apresenta uma proposta de antena de microfita envolvendo a inclusão de dois Anéis Ressoadores Complementares (Complementary Split Ring Resonator CSRR), bem como a variação das dimensões deste, e será realizado um estudo sobre sua influência nos parâmetros da antena de microfita, projetada através da Teoria de Linha de Transmissão, objetivando o incremento da largura de banda da antena e a filtragem de determinadas faixas de frequência a fim de fabricar um dispositivo que opere no sistema Ultra Wideband (UWB). A aplicação de múltiplas camadas dielétricas também será estudada a fim de se observar sua influência na perda de retorno da antena. Os resultados foram obtidos através de simulações utilizando o software ANSYS HFSS®, que utiliza o método dos Elementos Finitos, e os melhores resultados obtidos, juntamente com a análise do material disponível, foram utilizados para a fabricação dos dispositivos e medição dos mesmos a fim de validar as simulações realizadas. Os resultados das simulações se mostraram satisfatórios, pois a característica capacitiva do CSRR permitiu o filtro de algumas faixas de frequência, fazendo com que a perda de retorno tivesse característica dual-band. O resultado experimental da perda de retorno se mostrou concordante com o padrão simulado, apesar do deslocamento de frequência, porém apenas uma das antenas construídas se adequou para aplicação no sistema UWB, com largura de banda fracionária de 34,12% para a frequência de ressonância 4,35 GHz com perda de retorno no valor de -36,22 dB, permitindo a operação desta em diversos sistemas de comunicação wireless como padrões 802.11a, 802.11n, 802.11p entre outros sistemas

In the thesis presented, three novel uni-planar left handed transmission lines based on Complementary Split Ring Resonators (CSRR) and Complementary Spiral Resonator (CSR) metamaterial particles are proposed for the first time and successfully applied for the performance enhancement of conventional coupled line filters and the design of a full scan leaky wave antenna. Based on the implementation of Complementary Split Ring Resonators (CSRR) a fully planar Composite Right left handed transmission line (CRLH-TL) plus a Dual Composite Right Left Handed transmission line (D-CRLH-TL) are proposed, designed and studied. The CRLH transmission line is realized loading a microstrip host line with CSRR metamaterial particles and capacitive gaps on the conductor strip of the line, while the D-CRLH transmission line is built bridging the capacitive gaps between the CSRR's with inductive connections to induce dual propagation properties in the structure. A further performance enhancement is achieved by a second proposal based on the implementation of Complementary Spiral Resonators (CSRs). The studies applied to the structure reveal that conditions for D-CRLH propagation are created in a transmission line composed only by CSR metamaterial resonant particles as the result of the unique electromagnetic properties acquired by the CSRs etched on the conductor line of a microstrip waveguide. The CSRR/CSR based D-CRLH transmission lines proposed are applied in the design of two enhanced coupled line filters. The implementation is possible for the first time in this work as result of the highly versatile layout features of the left handed transmission lines proposed which among other important geometrical features, allows couplings in both sides of the structure. Enhanced filtering features are reached by the metamaterial based coupled line filters proposed in terms of selectivity and size reduction in comparison with conventional coupled line filters. In the case of the CSRR loaded metamaterial coupled line filter a size reduction of 49% is achieved compared with a filter of similar performance. A further enhancement is reached by the second coupled filter proposed based on CSR metamaterial resonant particles. The CSR coupled filter proposed reach a roll off rate improvement of 8 dB/GHz and size reduction of 43% in comparison with a conventional coupled line filter of the same order. When this is compared against a conventional coupled line filter of similar performance but higher order, a remarkable size reduction of 77% is achieved by the proposed CSR coupled line filter. Finally, the CSR loaded D-CRLH transmission line is applied in the design of a fully planar leaky wave antenna. Using the CSR structures etched on the conductor line of a microstrip as part of the radiation mechanism altogether with the D-CRLH propagation features of the structure. A full scan radiation pattern is created with backward, forward and broadside radiation as result of the left handed propagation band, right handed propagation band and the balanced transition between them. Two leaky wave antennas are designed to operate at the centre frequencies of 12.5GHz and 6.0GHz. In order to corroborate the performance the CSR D-CRLH leaky wave antenna operating at 6.0GHz is fabricated and measured showing a scanning range of 30 deg with a maximum gain of 13.2 dBi.